The move followed condemnation from church and political leaders over a decision to prevent check-in worker Nadia Eweida from wearing a cross at work.

Miss Eweida said: "This was a surprise to me. BA gave me no notice of the decision. But naturally I am very happy and grateful to the church, the public and the media, particularly the Daily Mail, for their support.

"This is not about me, it is about the rights of Christian workers throughout British Airways and beyond to be able to demonstrate their faith.

"Christians have been given a raw deal. I don't believe that any person from any other faith would have been treated in the way that I was."

Miss Eweida has effectively been prevented from working since September after being told by a supervisor that she could not wear a cross and chain over her uniform.

The decision to reverse this policy is a remarkable climbdown for BA, which had initially insisted that there could be no change to its uniform rules.

British Airways chief executive Willie Walsh suggested the airline had been caught in the midst of a furore through no fault of its own.

He said: "Unintentionally, we have found ourselves at the centre of one of the hottest social issues in current public debate."

He said the company had decided to change its policy after extensive consultation with its own staff and religious groups including representatives from the Church of England, the Catholic Church and the Muslim Council of Britain. One option considered was to allow staff to wear a lapel pin. Mr Walsh said:

"Most of those consulted felt that a lapel pin was an acceptable and reasonable option. For the majority of our staff, this was the preferred option.

"However, some respondents believed that limiting the change to a pin would not satisfy all Christians."

Importantly, he added: "Comparisons were made between the wearing of a cross around the neck and the wearing of hijabs, turbans and Sikh bracelets.

"For this reason, we have decided to allow some flexibility for individuals to wear a symbol of faith on a chain.

"Our uniform is one of the most powerful symbols of our company and heritage. Our staff wear it with pride and our customers recognise and value it.

"This modification will enable staff to wear symbols of faith openly without detracting from the uniform."

A BA spokesman confirmed that Miss Eweida would be allowed to return to work wearing a cross and chain.

Miss Eweida said she would be happy to return. "I will do my best to fit in and continue working in the way expected of me," she added.

"It has been a very tough time for me. My dignity was violated and I have struggled financially."

Her case was taken up by 13 bishops, including the Archbishop of Canterbury, and several members of the Government who threatened to boycott BA.

Last night the Archbishop of Canterbury, Dr Rowan Williams, said: "I am grateful that BA have listened to the deep concerns that have been expressed about this issue.

"Important issues have been raised; this is a positive and constructive outcome."

The director of the civil rights group Liberty, Shami Chakabarti, said: "At a moment when Britain's reputation as a tolerant democracy is under such scrutiny around the world, it's very good news that the airline that bears the name of our country is setting a good example."